Wireless charging refers to a power transmitter transferring energy wirelessly to a power receiver. For example, a power transmitter may be implemented as a so-called charging plate. In this example, when another device is placed on the charging plate, the power transmitter transfers energy to the other device (i.e., the power receiver). In this way, the other device can be charged. Wireless charging may work based on the principle of inductive charging, although other technologies may be used as well including magnetic resonance based charging. The power transmitter may include a primary coil which when energized induces an electromagnetic field into the adjacent secondary coil in the power receiver.